Aluminum pots are fine for brewing beer. Just don't polish them clean after use. You want to see an oxidation layer on the bottom, kind of a brownish layer is desired to keep the metal's integrity. They transfer heat very well and will last a lifetime if maintained properly. Me personally, I prefer stainless but it's a personal choice.

They are dirt cheap. Buy bigger than you think you'll need. instawares.com

I bought a 60 quart so I can boil 10 gals with room to spare. Not sure how I ever did it before in a smaller one. I've done a few brews in this one now and it works just fine. I'm following the advice above and basically wiping out the pot after the boil but not scrubbing it and it is working just fine.I couldn't spring for stainless of this size, it was 2-3X the cost at my local restaurant supply. Nice to have but not need to have.

I still use the 30qt aluminum turkey pot for a HLT. I got a dirt cheap 60 qt SS for the boil. Some times I have to use my 60qt for the strike with 11 gallon batches. The 30 is still big enough for the sparge.

The drawbacks of aluminum are that most aluminum pots are fairly soft, so are vulnerable to scratching and denting. They can also be depassivated or pitted if you use particularly harsh cleansers on them. Finally, aluminum also isn't good for cold-side usage because long-term exposure to acidic solutions (i.e., beer, which has ~ pH 3.2 - 4.8, or wort, which has pH 5.6 or lower) leach metal ions into your beer, giving metallic off-flavors.

Stainless is preferred in commercial breweries because of its durability and ease of cleaning, but there's no reason you can't use aluminum or even copper for your hot side operations.

Most SS pots these days have tri-clad bottoms, i.e., a 3 or 4 mm Aluminum disc sandwiched by thin sheets of SS. As aluminum is so much more conductive than SS, this helps with thermal transfers and even heating along the bottom of the kettle. When you can afford it, I think it is worth springing for it.

Most SS pots these days have tri-clad bottoms, i.e., a 3 or 4 mm Aluminum disc sandwiched by thin sheets of SS. As aluminum is so much more conductive than SS, this helps with thermal transfers and even heating along the bottom of the kettle. When you can afford it, I think it is worth springing for it.

The higher quality SS pots do have tri-clad bottoms. The cheap ones don't. Generally, you can determine the quality of a SS pot by weight - thicker walls and clad bottom. And, yes, it's worth paying for - especially if you have a really powerful burner under your pot.